Character adding device for typewriting equipment



United States Patent O O0667O O6 BBH 0 H BHH777H 7 77990 7 9 99 9 11. 1

mm at we mm n ma RC 57 66 99 ll 83 6 8 0 3 ,763 12/1942 Dietrich 478 2/1953 Simon 541 11/1962 Hartnett et al... 2/1964 Ryan et al........

,889 10/1967 Barger.......................... 3,432,018 3/1969 Watanabe et a1. Primary ExaminerEdgar S. Burr L a I e s S u a r K 7 6 9 l 7 6 2 5. 2 3 3. 3

1,978,068 10/1934 Weniger....................... 2,305

[72] lnventor Robert H. Twyl'ord Falls Church, Va.

[21] Appl. No. 707,774

[22] Filed Feb. 23, 1968 [45] Patented Dec. 15, 1970 [73] Assignee Mechanical Enterprises, Incorporated a corporation of Virginia [54] CHARACTER ADDING DEVICE FOR TYPEWRITING EQUIPMENT 23 Claims, 13 Drawing Figs.

197/36 B4lj H32 ABSTRACT: A device for facilitating the addition of such a [56] References Cited UNITED STATES PATENTS character in typewritten material as is not normally included in standard typewriting equipment. This device is intended for use in typewriter equipment having a single printing head.

CHARACTER ADDING DEVICE FOR TYPEWRITING EQUIPMENT BACKGROUND or THE INVENTION l. Field of the invention This invention relates to a device for applying or inserting in typewritten material desired characters, such as letters, signs, symbols and the like. More specifically, this invention is directed to a device cooperative with typewriter equipment having a single p lingflhead to facilitate the insertion of type characters, not'carri ed by said head,' in conjunction withthe conventional operating procedure of the typewriter equip ment.

2.-State ofthe Prior Art In recent years, the typewriter equipment field has been advanced by the entry therein of typewriters employing a single printing head or element. While such single printing head typewriter equipment is designed to permit the interchange'of printing heads to thereby provide for the utilization of a plurality of type fonts, such heads provide acollection of characters far more extensive than is normally required and are therefore relatively expensive. Furthermore, the removal of such ahead from the typewriting equipmentis time consuming and causes the operator to come in contact with the ribbon ink on the head potentially resulting in unclean typewriting conditions.

In normal practice, there arises the necessity of inserting certain specialized characterssuch as letters, signs, symbols,-

,heads will not'correspond with the letters displayed on the standard typewriter keyboard, such that'a comparison chart must be studied to determine the keyboard key that will print a desired character on the substituted heador decals identifying the characters on the substituted head must be applied to the typewriter keys so that the operator will be informed that a particular character will be printed by-depressing a particular key on the keyboard. It is, therefore, the practice to insert such specialized characters. by hand thereby detracting materially from the overall general appearance and neatness of the finished typewritten product. 1

While the prior art has provided certain devices for insening additional characters in typewritten material in relation to other and more standard typewriter equipment, it is my opinion that no such devices are presently available for use with typewriting equipment employing a single printing head nor may the other aforementioned prior art devices by adequately adapted to use on single printing element typewritercquipment.

SUMMARY or rue INVENTION This invention encompasses a device to facilitate the applitively moving the head to locate a single type character on said head in a printing position. This typewriting equipment further includes a rocker platform which supports the single printing head and means cooperative with said platform for rocking the platform to thereby drive the printing head a first distance toward the platen, said means then releasing said head, allowing the printing head to move by inertia a second distance into printing engagement with the ribbon and platen for printing the selected type character on a type-receiving material carried by the platen.

A type adding device encompassed by this invention includes a type character adding member in combination with a support member for releasably mounting the character adding member in cooperative relation with the rocker platform and printing head. The type character adding member includes a handle portion to facilitate its insertion and withdrawal and a type carrying portion, the type carrying'po'rtion having at least one surface with at least one type character located thereon. The type carrying portion is located between the platen and the printing element, said element pressing the character carrying portion into printing engagement with the ribbon when said element is activated.

It is an object of this invention to alleviate the aforementioned difficulties in the art by providing a new and novel device for inserting additional type characters in typewritten material produced in typewriting equipment employing a single printing head. 7

A further object of the present invention is to provide such a device which may be quickly and easily installed on conventional typewriting equipment without modification of the equipment or the necessity for obtaining the services of a typewriter mechanic.

Another object of the present invention is to provide such a device which is easily adjustable in order to accurately align the type character carried by the said device-with the type character of the printing head located in the printing position to properly position the printed image of the. added character on the type receiving material carried by the platen of the typewriter.

It is a further object of this invention to provide such a device having a support member for providing a stable mounting for the character carrying member in-thetypewriting equipment in order to provide a distinct printed image of the character. It is also an important object of this invention to provide such a device having the support member mounted on the rocker platform of a single printing element typewriter in such a manner that the type character onv-said type carrying member may be properly aligned and positioned relative to the printing head and theplaten'and wherein said support member and said character carrying member moves with said rocker platform and printing head to provide a distinct, properly aligned printed image. The movement of the type carrying member with the rocker platform and printing ele ment of the typewriter is deemed important in achieving precise printing of the typecharacter to be added.

An additional object of this invention is to provide such a device having a character carrying member with that portion of the character carrying member which is struck by the printing head and forced into printing engagement by said head with the ribbon and platen formed of a resilient material in type characters on the character carrying member having a type character carrying portion comprised of first and second layers, said first layer being opposite the printing head and. formed of a resilient material and said second layer being opposite the platen and comprised of a metallic material, said metallic layer defining the type character.

Another object of this invention is to provide such a device wherein the character carrying member defines a bore therein and wherein the support member includes a portion slideably receivable in said bore to thereby facilitate the accurate positioning of the character carrying member in relation to the platenand the printing head in an easily engageable and releasable manner.

Other objects and advantages of the new and novel features of this invention will become apparent from the following BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is afragmentary sectional view taken through the rocker platform and platen of a conventional single printing element typewriter with the type character adding device of this invention mounted in said platform and the ribbon-feed normally located between the printing element and platen omitted. FIG. 2 is a perspective view of the support member of the character adding device.

' FIGJ3 is a perspective view of an adjustable collar member which threadingly engages the support member of FIG. 2.

FIG. 4 is a perspective view of the type carrying member.

1? IG. 5 is a plan view of the type carrying member illustrated in .lFIG. 4 shown in relation to a printing head illustrated by broken lines. p 6 is a fragmentary sectional view taken on line 6-6 of FIG. 5 showing the type carrying portion of the type carrying msm )IFIG. 7 is a fragmentary sectional view of a modified form of support member of this invention.

FIG. 8 is a plan view of the sleeve member of the collet assembly shown in FIG. 9.

EIG. 9 is a sectional view of the sleeve assembly.

10 is a perspective view of the expander nut for the collet assembly. v "gElG. 11 is a sectional view through the type carrying portion ofa modified type character adding member shown positioned between a printing element and a platen with the ribbon normally located between the printing element and platen, omitted.

member of the collet 1510. 12 is a sectional view taken on line 12-12 of FIG. 11

. and,

FIG. 13 is a perspective view of the leg member 50 of the modified type character adding member of FIG. 11 and 12.

. 1 DETAILED DESCRIPTION OF THE INVENTION "The character adding device of this invention as illustrated ineither of th embodiments shown in FIGS. 1 or 9 is adapted for utilization with conventional typewriting equipment of the single printing element type. The aforementioned embodiments of this invention may be installed on such conventional typewriting equipment without modification of the equipment and may be utilized in accordance with the standard operating procedures associated with such equipment.

' Referring to FIG. 1, a portion of a conventional single element typewriter is illustrated of the nature of that illustrated a'n'd described in the U.S. patent to Palmer et al., U.S. Pat. No. 2,879,876, issued Mar. 3 l 1959. Conventionally, this typewriter equipment broadly designated by the reference numeral 1 includes a typewriter platen 2, a single printing elemen: or head 4 operatively supported on a rocker platform 6 with a .cam assembly 8'for actuating the rocker platform 6. Normally; a conventional ribbon-feed assembly is located between the printing element 4 and the platen 2; however, in order to clearly illustrate the inventive concepts embodied in this-disclosure, such a feed assembly has been omitted.

The printing element 4 contains rows and columns of raised type characters 10 on its exterior surface which normally coma particular type font. By striking a particular key on the of such typewriting equipment, the printing element 4'iis' rotated and tilted on its supporting post or pedestal 12 from. an initial or base position to locate the desired type character in a predetermined printing position opposite the platen 2. Normally, the element is returned to its base or initial position after each printing operation. The mechanism for moving the selected type character to the printing position may take various forms such as that disclosed in the aforementioned Palmer et al. patent or as illustrated in the U.S. patent to Becker et al., U.S. Pat. No. 2,926,768, issued Mar. 1, I960.

Referring to FIG. 1, the rocker platform 6 as illustrated, is swingable about a hollow bushing 14 in a clockwise direction from the position shown thereby moving the'printing element 4 into printing engagement with the platen 2. The rotation of the platform6 is effected by the cam assembly 8 illustrated herein as comprised of a cam 16 operatively mounted on a rotatable shaft 18 in a conventional manner, a printing cam follower 20 and a cam link 22. The cam link 22. is swingably mounted to the platform 6 by a pivot pin 24 and is rotatable about a fixed pivot 26 received through an elongated slot 28 defined in the cam link 22. The cam l6-includes a single cam lobe which, upon counterclockwise rotation, pivots the link 22 about the fixed pivot 26 and drives the link 22 toward the platen 2 causing the platform 6 to rotate clockwise about the bushing 14.

The cam assembly 8 is specifically designed to rotate the platform 6 through an arc of a predetermined length in order to drive the printing element 4 a first distance through a portion of the printing stroke toward the platen 2. This first distance is less than the at rest spacing between the printing element 4 and the platen 2; therefore-the element 4 is not driven under power fully into printing engagement with the platen 2. The printing element 4 and platform 6 are released from the driving action of the cam assembly 8 and by the momentum imparted through the initial driving force the element 4 moves into printing-engagement with the platen 2. This release point normally occurs with the raised face of character 10 on head 4 spaced about 0.03 to 0.05 inches from the platen 2 and the maximum distance of 0.05 inches may be considered as the upper limit for accommodating a member inserted between the head 4 and the platen 2 and still have the typewriter function properly in movements of the head and rocker platform 6. The printing element 4 and the platform 6 are then free to rotate in a counterclockwise direction about bushing 14 to return to their initial position. Various means such as springs may be employed to accelerate the return of the platform 6 and element 4. The aforedescribed operation of the printing element is conventional inthe art and may be accomplished by various types of actuating mechanisms in order to provide the desired result of driving the printing element 4 the first distance toward the platen 2 and allowing the element 4 to move by momentum into printing engagement with the platen 2.

Conventionally, the rocker platform 6 is provided with a through bore 30 having a substantially upright axis and including a threaded portion 32. A type character adding device encompassed by this invention may be adapted to utilize the bore 30 as a part of the mounting.

While I have illustrated two embodiments of my invention wherein the character adding device is operatively mounted to the rocker platform 6 employing the provided bore 30, it is.

contemplated that the character adding device could be mounted in other locations in the typewritingequipment. It is, however, particularly noted that certain advantages are obtained by the mounting of the character adding advice to the rocker platform. Aside, from the ability to install thedevice without the necessity of modifying the typewriterequipment, the movement of the type character adding device in unison with the rocker platform 6 and the printing element 4 prevents relative movement between the various parts which could swing laterally or otherwise vary the printing stroke of the character adding device to thereby prevent a blurring of the printed image which would result from such variations in the printed stroke.

Referring to FIG. 1, a type character adding device embodying the features of this invention is illustrated and is broadly designated by the reference numeral 40. The

character adding device 40, as illustrated, is comprised of a support member 42- and a type character adding member 44 releasably-mounted on the support member 42 in such a manner that it may be easily inserted and withdrawn from its operative position on the supporting member 42.

Referring to FIG. 4, the type character adding member 44 is illustrated as substantially L-shaped, having an upright stern member 46 defining a handle portion 48 and an outwardly directed leg member 50, including a type carrying portion 52. The upright handle portion 48 permits the operator to install and withdraw the member 44 without contacting the ribbon ink and in a relatively expeditious manner. Handle portion 48 also displays at 49 the same type character as is formed on type carrying portion 52 so that the user of device '40 may conveniently visually observe the particular character to be added by noting the character displayed on handle portion 48. For purposes of illustration, the type character adding member 44 shown on FIG. 4 willprint and displays on its handle at 49 the square root sign.

Referring to FIG. 5, the leg member- 50'of the type adding member 44 includes a forward surface 54 and a rearward surface 56. The forward surface 54 is positioned opposite the printing element 4 shown in dashed lines in FIG. 5 and is concavely contoured longitudinally of the leg member 50 complimentarily of the printing element 4. Thecontour of .the surface 54 of the leg member 50 assists in retaining the type character adding member 44 in the desired printing position when the rocker platform 6 and printing element 4 are moved toward the platen 2 and when the printing element 4 actually presses the character carrying portion 52 into printing engagement. The rearward surface 56 of the leg member 50 includes at least one type character 58 which is formed in raised relief on the type carrying portion 52 of the leg member 50. The type carrying portion 52 is accurately positioned between the platen 2 and the printing element 4 with theraised character 58 in aligned relation to the character in the printing position on the printing element 4.

Referring to FIG. 6, the type carrying portion 52 of the type character adding member 44 is illustrated in cross section, depicting a base 51 and a surface layer 53.. The base 51 is comprised of a resilient, synthetic resin material such as a polystyrene, having the type character 58 carried by said character portion 52 molded in raised relief from the surface 56. The base 51 and the remainder of the'type character adding member 44 maybe formed by a simple and inexpensive molding process. The surface layer 53 is comprised of a metallic material such as a layer of metal laminated to base 51. This metallic layer 53 is impressed into the synthetic resin base 51 whereby the metallic layer forms the typeface of the type character 58. If desired, the metallic layer 53 may be bonded to the base 51 by a bonding material or' formed around the edges of base 51 to firmly affix it to the base. The use of such a metallic layer, while not necessary to this invention, does provide for a type character having better wearing characteristics and also enhances the clarity or sharpness of the printed image. As is also indicated in FIG. 6, the surface56 of the type carrying portion 52 at least on that portion thereof defining the type character 58 is concavely contoured complimentarily to the platen 2 to enhance the clarity of the printed image. Also, as best shown on FIG. 6, the forward surface 55 is curved so that the curved face of the type character on the printing element 4 will mate therewith toeffectively press the type character 58 against the material receiving the typed information on the platen 2. I 1

The type character carrying portion' 52 of the type character adding member 44 has at its central portion an overall dimension including the type character 58 in a direction generally normal to the rearward or type carrying surface 56 which is no greater than the second distance of movement of the printing element 4 through its printing stroke. In this manner, the type carrying portion 52 does not prevent the printing element 4 from reaching its release point in the printing stroke and, therefore, does not bind or otherwise inhibit the operation of the printing element 4. This second distance, and accordingly the maximum thickness for portion 52 plus character 58, is, on present single head typewriters, in the order 0.03 to 0.05 inches but thus as previously mentioned, a maximum thickness of 0.05 inches can be accommodated for portion 52 plus character 58 without unduly inhibiting the operation of printing element 4 and rocker platform 6.

Referring to FIG. 2, the support member 42 is illustrated as a cylindrical shaft having first and second opposed end portions 62 and 64. The first portion 62 is comprised of a pin member 66 which is slideably received in the bore in the typewriting equipment. The second portion 64, as illustrated in FIG. 2, includes a threaded portion 68 which may be threadingly engaged with the threaded portion 32 in the bore 30 of the rocker platform 6 in order to retain the support member 42 in a substantially upright position and mounted to the rocker platform 6.

As illustrated in FIGS. 1 and 3, the supportmember 42 includes a second threaded portion 70 spaced from the threaded end portion 68 for receipt thereon of an adjustable collar 78. The collar 78 is threadingly engaged on said support member 42 and defines a supporting surface 80 disposed in contacting relation to the lower surface 82 of the type character adding member 44 thereby supporting the member 44 in a desired position at a desired elevation on the pin '66 of the support member 42. As shown in dashed lined in FIG. 1, the pin 66 need not be fully extending into the bore 60 as the support for the member 44 is provided by the collar 78. The collar 78 may be adjusted simply by rotating the collar 70 on the threaded portion of the support member 72 to thereby selectively raise and lower the type character adding member 44 to regulate the relative position of the type character carrying portion 52 and the printing element 4. p

This height adjustment capability is important to insure that the type character 58 on portion 52 of the type character adding member 44 will be imprinted in accurate alignment with thetyped line on the type receiving material-carried by the platen. Normally, the collar 78 would need to. be adjusted only once so that each successive type character adding member 44 when placed on pin 66 to rest on supporting surface 80 of collar 78 will be accurately aligned to apply its type character.

into the typed line on the type receiving material when actuated by movement of printing element 4 and rocker platform 6. To frictionally retain collar 78 in its once-adjusted position, a plastic insert may be imbedded in threaded portion 70 which will offer a frictional drag when engaged with the internal threads of collar 78 and firmly hold the collar in the desired adjusted position. This insert is not illustrated on the embodiment of FIGS. 1, 2, and 3 but is shown at 109 on the embodiment ofFIGS. 7, 8, 9, and 10.

The support member 42 defines an abutment surface 72 located between the threaded portions 68 and 70 to limit the depth of penetration of the support member 42 into the bore 30. Further,the support member 42 includes a tool-gripping portion 74 whereby the member 42 may be gripped by a tightening tool and rotated into engagement with the threaded portion 32 of the bore 30.

Referring to FIGS. 7, 8, 9, and 10, a modified form of the support member is illustrated and is broadly designated by the reference numeral 100. The support member 100, like the support member 42, has opposed end portions 102 and 104 with end portion 102 defining a pin member 106 which is slideably receivable in the bore 60 of the character adding member 44. Adjacent the pin ember 106, a threaded shaft portion 108 is provided for threaded engagement with the adjustable collar 78. A plastic insert 109 may be provided embedded in threaded shaft portion 108 to prevent frictional drag when adjustable collar 78 is threaded onto portions 108. Thus, when collar 78 has been moved to its proper adjusted position, it will be held against moving therefrom by vibrations 'of the typewriter in operation. "member 100 further includes a tool-gripping portion 110 posi- As illustrated, the support tioned beneath the threaded shaft portion 108 to be gripped '42 in itsmanner of attachment to the rocker platform 6. Due to variations in the dimensions of the through bore 30 and/or fthreads 32 found in the rocker platform 6 in standard l'typewriting equipment, it is desirable to provide means for securing the support member 100 to the rocker platform 6 {which is adaptable for attachment in bores of varying dimen- '"sions or where threads 32 are not fully formed at the lower end ,;of such bore. The support member 100 is therefore provided with an expansible collar assembly 112 at its end portion 104 {which is received in the through bore 30 and expandable into abutting relation with the side walls of the bore 30 in order to securely retain the mounting member 100 in a desired and stafble position on the rocker platform 6.

I The expansible collar assembly 112 as illustrated is comprised of a sleeve member 114 having opposed end portions 116 and 118 with a plurality of slots 120 defined in the side wall of the sleeve member and extending inward from each of the sleeve 114. The assembly 112 further includes a pair of opposed, spaced outwardly tapering surfaces, 122 and which engage in the opposed end portions 116 and 118, respectively, of sleeve member 114. In this manner, when the opposed tapering surfaces 122 and 124 are moved inwardly of the bore defined by sleeve 114, the opposed end portions 116 -;and 118 of the sleeve member 114 are expanded outwardly by the force exerted by means of the tapering surface 122 is defined by a portion of the support member 100. The lower ataipering surface 124 is provided on an expander nut 125 -threadingly engaged on a threaded shaft portion 126 of the isupport member 100. I

In order to install the support member 100 in a bore 30 in i'the rocker platform 6 in standard typewriting equipment, the r:tightening nut 125 is first tightened to expand the sleeve 114 "to:a point where the sleeve snugly fits into the bore 30. The expandable collar assembly is then pressed into the bore 30 and the member 100 rotated by gripping the tool-gripping portion l. 10, thu's causing relative movement between the nut 125 and the threaded shaft portion 126 resulting in an expansion of the sleeve member 114. The sleeve member-114and the nut 125 areretained in position during rotation of the member 100 by their frictional engagement with the side walls of the bore 30 effected by the snug fit of the sleeve in thebore.

The character adding device 40 is installed in standard "typewriting equipment merely by engaging either the support members 42 or 100 in the bore 30 of the rocker platform 6 in the manner previously described. With either'of the support members 42 or 100 so mounted, individual character adding members 44 may be releasably connected to the support nrember 42 or 100 simply by receipt of the pin member 66 or 106 in the bore 60 define by the character adding member 44. The elevation of the character adding member 44 may be varied by rotation of the adjustable collar 78, as previously discussed in order to properly align the added character 58 up with the typed line on the type receiving material carried by the platen 2. As the individual character adding members 44 will be dimensionally similar, it should only be necessary to set the adjustable collar 78 at the proper elevation initially.

The operator can easily withdraw the character adding member 44 simply by grasping the handle portion 48 and sliding the member 44 off of the pin member 66 or 106. Although pin members 66 and 106 have been illustrated, to engage with a bore 60 in the character adding member 44, it will be appreciated that the pin member could be carried by the character adding member 44 for insertion .in bore 30 in mounting the device on therocker platform 6 instead of having a separate pin member more or less permanently mounted on the rocker platform.

A modified type character adding member is illustrated in FIG. 11, 12, and 13. The member on this modification generally has the overall configuration and features of the member 44 as heretofore described and shown in perspective on FIG. 4. The difierence in the modification resides in the configuration of the type carrying portion 52 at the end of the outwardly directed leg member 50. The modified type character adding member will be mounted on the typewriter for use in a manner similar to the mounting approaches heretofore described or mentioned with reference to the type character adding member 44 of the first embodiment.

The type carrying portion 52 on leg member 50 of the modified member may be provided with a surface layer 53 as in the first embodiment, this surface layer being of a metallic material laminated, bonded or otherwise secured on the base 50. Also as in the first embodiment the rearward surface of the leg member 50 will be at least one type character 58 formed in raised relief on the type carrying portion 52. The printing face of the type character 58 in both embodiments is cylindrically curved as shown in FIG. 6 and 12 to mate with the curvature of the platen 22 such that upon being'pressed against the platen with the ribbon and type receiving material interposed between the type character 58 and platen a well defined clear imprint of the type character will be applied on the type receiving material.

Instead of having the generally smooth curved forward surface 55 as illustrated on FIG. 6 for the first embodiment, the forward surface of the type carrying member 52 of the modified type character adding member has, as more clearly illustrated in FIG. 13, a generally rectangular rib formed thereon. This rib in the form shown is comprised of upper and lower walls 130 and a pair of side walls 132. Together these four walls define a recess 134, within the rectangular rib.

In the preferred'construction of the embodiment of FIGS. 11, 12 and 13 the recess 134 defined between forwardly projecting walls 130 and 132 will be of sufficient depth such that as shown in the sectional views of FIGS. 11 and 12 the type character 10 on printing element 4 will, when the element presses the type character 58 toward the platen, pass into recess 134 but type character 10 will not be of sufficient height to engage the bottom of recess 134. In this relationship the four walls 130 and 132 forming the forwardly projecting rib will engage with the surface of the printing element 4 which surrounds the base of the raised type character 10.

As previously discussed with reference to the first embodimerit, the maximum thickness of 0.05 inch permissible for interposition between the printing element and the ribbon and platen is measured at the center portion of the type carrying portion 52. This is true irrespective of whether a forwardly projecting rib is employed as contemplated in the modified embodiment. In the modified embodiment the center portion 52 is preferably slightly less than 0.05 inch since the bottom of recess 134 is not to' engage the face of the raised type character 10, the raised rib holding the bottom away from character 10 as shown in FIGS. 11 and 12. This insures that the printing force is applied through the forwardly projecting rib.

Thus more widely distributed pressure maybe transferred from the printing element to the perimeter of the type carrying portion 52. This can be advantageous where, a relatively large or intricately detailed type character 58 is provided on type carrying portion 52 to be added into typed material. The large the type element 44 presses against the forward ends of the walls 130 and 132 forming the rectangular rib on type carrying portion 52.

To insure most effective application of pressure from the generally spherical printing element 4 to the rectangular rib on type carrying portion 52, the forward surfaces 136 of the four walls 130 and 132 are preferably contoured such that the rectangular rib presents an overall surface configuration which will mate a sphere having a diameter such as possessed by printing element 4 without the rib type characters on the exterior surface of the printing element. With the surfaces 136 contoured to provide the rib with this spherical mating configuration, it will be appreciated that the rib will evenly engage with the spherical surface of printing element 4 at the perimeter of the base of the type character 10 which extends into recess 134. Thereby most uniform application of printing pressure will be applied to press the character 58 to be added agai'nstthe ribbon and then imprint it on the type receiving material carried by platen 2.

Although a full rectangular rib made up of walls 130 and 132 has been illustrated it should be pointed out that certain characters 58 may not require the application of printing pressure distributed in a full rectangular pattern to achieve the desired preciseness and clarity in the final printed results. In this regard, for certain sizes or arrangements of type characters 58 only top and bottom walls 130, omitting the sidewalls 132, or in other instances only side walls 132, while omitting top and bottom walls 130, may be provided. In each altemative it still is preferred that the forward surfaces 136, or the particular two walls that are employed, be contoured to conform and mate with the spherical surface on the printing element.

The modified character adding member provides distinct advantages where a particularly large or intricate character is desired to be added into typed material. In such case the rectangular rib or pair of walls protrude forwardly on the type 2 portion 52 and better force application and its distribution may be achieved. The first embodiment is, however well suited for the great majority of characters which will be called for, to be added into typed material. The relatively smooth curved surface 55 on the type carrying portion 52 of the first embodiment allows free movement of printing element 4 when the element orients to dispose the different raised characters opposite the platen in accordance with the keys on the typewriter keyboard that are depressed. This orienting movement does take place when keyboard keys other than the lower case z on the typewriter are struck. In its normal stationary position on the current IBM Selective Typewriter, the lower case letter z on the printing element is disposed opposite the platen such that when the lower case 2 is depressed the printing element 4 moves toward the platen without rotating or swinging about its center.

With the type character adding member of the first embodiment orienting movements of the spherical type element 4 are of no concern since the raised type characters 10 may pass freely over the smooth curves surface 55 of the type carrying portion 52 before the type element 4 is pressed against portion 52 to print character 58 on the type receiving material. Thus any letter on the typewriter keyboard may be depressed to actuate a device in accordance with the first embodiment and indeed it may be desirable, depending upon the disposition of the character 58 on the surface of the type carrying portion 52, to select a particular key to actuate'a particular character adding device for clearest printing of the particular type character 58 on the device.

With the second embodiment it is preferred that the key for the lower case 2 be depressed since the spherical printing element 4 does not orient when this key is depressed. In such operation the raised letter z passes directly into recess 134 and the element 4 presses the character 58 into the type receiving material. Orienting movements of the spherical printing element 4 could brush the raised type characters 10 across the surface of the rib formed by one or more'of walls 130 or 132 suchthat damage could result to'the rib whichpreferably is formed of a plastic material to insure that nodamage can be done to the raised metal type character on printing element 4.

Many variations and modifications of the present invention will occur to those skilled in the art from a study of the invention specifically disclosed herein. All such variations and modifications which come within the spirit and scope of the appended claims are intended to be included herein as fullyand completely as if they had been specifically illustrated, described and claimed. Thus, the modifications specifically disclosed are exemplary only and not intended to be limiting on the scope of the invention.

lclaim: i

l. A device to facilitate applying an additional character in typewritten material produced by a typewriter, *having a platen, a ribbon-feed assembly for positioning a ribbon in printing relation to a type receiving material carried by said platen, a single printing element having at least a font of type characters arranged thereon, means connected to said element for selectively moving said element to locate a desired character on said element in a predetermined printing position a rocker platform supporting the printing element and, means for selectively rocking said platform to drive the printing element a first distance and release said element to permit the momentum of said element and platform to move the element a second distance into printing engagement with the ribbon for printing the selected type character on the type receiving material carried by said platen, said device comprising:

a type character adding member having a handle portion and a type carrying portion, said handle portion and said type carrying portion being connected to one another, said type carrying portion having at least one surface with a type character thereon and reducing in thickness in a direction normal to the type carrying surface from a first thickness at said handle portion to a second thickness at said type character, said second thickness and the thickness of said type character together being no greater than the second distance of travel of said printing element; and I a member for supporting said character adding member including means for releasably and adjustably mounting said character adding member in cooperative relation to the typewriter to accurately position said type carrying portion between the printing element and the platen with the type character on the character carrying portion of the type character adding member aligned with the desired character of the printing element when the desired character is in said predetermined printing position.

2. The device recited in claim 1 wherein said second thickness and the thickness .of said type character is no greater than 0.05 inches.

3. The device recited in claim 1 wherein the character adding member is substantially L-shaped, having an upright stern member and an outwardly directed leg member, said leg member including the type carrying portion and said stern member defining the handle portion of the character adding member.

4. The device recited in claim 1 whereinsaid mounting member has opposed end portions, one of said end portions including means for releasably engaging said type character adding member and said other end portion being comprised of a threaded shaft.

5. The device as recited in claim 1 wherein the character carrying portion of the character adding member includes a base portion defining at least one type character in raised relief on one surface thereof and a thin" metallic layer overlying said surface of the base portion and impressed about said raised character whereby said character is defined by said outer metallic layer.

6. The device as recited in claim 1 wherein the character carrying portion of the type character adding member includes forwardly projecting wall means on the forward surface of said character carrying portion to engage with the printing element adjacent the base of one of the type characters on the printing element. r v

7. The device recited in claim 1 wherein said mounting member has opposed end portions, one of said end portions including'means for releasably engaging said type character adding member and the other of said end portions including a shaft, an expansible collar, and means on said shaft for expanding said collar whereby said expandable collar may be received in a bore defined in a part of the typewriter equipment and the collar expanded into abutting relation with the side walls of said bore to retain said mounting member in a desired position.

8. The device as recited in claim 7 wherein said collar is comprised of a sleeve member defining a bore in which said shaft is received, saidsleeve member having a plurality of slots extending inwardly thereof from each of the opposed ends of said sleeve member and wherein said means for expanding said collar is comprised of a pair of opposed, spaced outwardly tapering surfaces having inner opposed ends receivable in said sleeve at its opposed ends respectively, said tapering surfaces having outer end portions of a diameter greater than the diameter 'of the bore defined by said sleeve and wherein a porshaft varies the spacing between said tapering surfaces causing said tapering surfaces to move inwardly and outwardly of the bore defined by said sleeve thereby expanding and contracting said sleeve respectively whereby said sleeve may be moved in and out of abutting relation respectively of said side walls of {the bore in the part of said typewriter equipment.

9. The device recited in claim 1 wherein the character adding member defines a bore therein and wherein said mounting member has a first portion slideably received in the bore of i the character adding member for releasably retaining said character adding member to said mounting member. I 10. The device recited in claim 9 wherein said mounting member further includes'adjustable means for adjustably varying the relative position of the portion of said connecting .means received in said bore, axially of said bore whereby the .character adding member may be accurately positioned rela- ,tive to the printing element and to the line of type on the typed material carried by said platen.

shaft positioned below the first portion of said support member and a threaded adjustable collar, threadingly engaged .on said shaft, said adjustable collar having a surface to supporting by contact the character adding member whereby said adjustable collar may be rotated on said threaded shaft :thereby varying the relative position of the character adding member on the mounting member.

12. The combination in a typewriter comprising:

a frame;

a platen operatively mounted on said frame;

a rocker platform mounted on said frame adjacent said platen;

a printing element having at least a font of type characters arranged thereon mounted on said "rocker platform in spaced relation from said platen; I

a type character adding member having a handle portion and a type carrying portion, said type carrying portion being positioned in the space between the printing element and the platen, said type carrying portion having at least one surface with at least one type character thereon, said type carrying surface being located opposite said platen; and

means mounted on said rocker platform for releasably pivotally mounting said character adding member on said rocker platform with said character carrying portion of said member accurately positioned between the printing element and the platen, in aligned relation to a selected type character on the printing element when said element character is in the printing position, said type character adding member being movable with said printing element and rocker platform and pressed into printing engagement between said printing element and said platen to print a type character on a type receiving material carried by the platen.

13. The combination as recited in claim 12 wherein the character carrying portion of the type character adding member includes forwardly projecting wall means on the forward surface of said character carrying portion to engage with said printing element adjacent the base of one of the type characters on said printing element.

14. The combination as recited in claim 12 wherein the rocker platform defines a threaded bore having a substantially upright axis and wherein said mounting means includes one end portion comprised of a threaded shaft, said shaft being received in said bore in threaded engagement to retain said mounting means in position on said platform.

15. The combination as recited in claim 12 further including means for driving the rocker platform and the printing element said driving means driving said element toward said platen a first distance, the driving force then being released and the printing element moving a second distance and into printing engagement with the ribbon by the momentum imparted by the initial driving force and wherein said type carrying portion of said type adding member has a dimension substantially normal to the type carrying surface which is no greater than the second distance of movement of the printing element.

16. The combination as recited in claim 12 wherein the character adding member is substantially L-shaped having an upright stem member and an outwardly directed leg member, said leg member including the type carrying portion of said device and said stem member defining the handle portion of said device.

17. The combination as recited in claim 16 wherein the leg member of said L-shaped carrying type device has a forward surface opposite the printing element of the typewriter and a rearward surface opposite the platen and wherein said forward surface is complimentarily contoured to said printing element and wherein said rearward surface defines at least one type character.

18. The combination as recited in claim 12 wherein said means for releasably mounting said character adding member on said rocker platform is comprised of a support member having a first portion slideably received in the bore of the character adding member and a second portion, including means for connecting said support member to said rocker platform.

19. The combination as recited in claim 18 wherein the rocker platform defines a bore having a generally upright axis and wherein said support member has the lower end of its second portion received in said bore and wherein said means for connecting said support member to said platform serves to retain said support member in said bore.

20. The combination as recited in claim 18 wherein said support member further includes adjustable means for selectively varying the elevation of the character adding member on said support member whereby the character carrying portion of said character adding member may be accurately positioned relative to the printing element and the platen.

21. The combination as recited in claim 20 wherein said adjusting means includes a threaded shaft positioned below the first portion of said support member and a threaded adjustable collar threadingly engaged on said shaft, said adjustable collar having an upper supporting surface in engagement with the character adding member whereby said threaded adjustable collar may be rotated on said threaded shaft thereby varying the elevation of the type character adding member and thereby the relative position of the type character carrying portion of said type character adding member to the platen.

22. The combination as recited in claim 12 wherein the rocker platform defines a bore and wherein said mounting means includes a support member having one end portion comprised of a shaft, an expansible collar and means on said shaft for expanding said collar into abutting relation with the side walls of said bore to retain saidmounting means in position on said plafiorm.

23. The combination as recited in claim 22 wherein said collar is comprised of a sleeve member defining a bore in which said shaft is received, said sleeve member having a plurality of slots extending inwardly thereof from each of the opposed ends of said sleeve member and wherein said means for expanding said collar is comprised of a pair of opposed, spaced outwardly tapering surfaces having inner opposed ends receivable in said sleeve member at its opposed ends respectively, said tapering surfaces having outer end portions ol. a diameter greater than the diameter of the bore defined by said said tapering surfaces causing said tapering surfaces to move inwardly and outwardly of the bore defined by said sleeve thereby expanding and contracting said sleeve respectively to move said sleeve in and out of abutting relation respectively of said side walls of the bore in said rocker platform. 

